identify a customer's traffic while traversing the provider network to multiple remote sites. The device
uses the VLAN membership of the switch port client (the customer VLAN ID, or C-VID) to perform a
lookup on a corresponding S-VID.
To access this page, click
Switching
>
DCHP Snooping
>
L2 Relay
>
VLAN Configuration
in the
navigation menu.
Use the buttons to perform the following tasks:
•
To enable a VLAN for DHCP Layer 2 relay, click
Add
and select the VLAN from the available menu.
•
To update the DHCP Layer 2 relay settings for one or more VLANs, select each entry to update and
click
Edit
. The same settings are applied to all selected VLANs.
•
To disable one or more VLANs as DHCP Layer 2 relay agents, select the appropriate VLANs and click
Remove
. You must confirm the action.
Table 191: DHCP L2 Relay VLAN Configuration Fields
Field
Description
VLAN ID
The VLAN associated with the rest of the data in the row. When configuring the
settings for one or more VLANs, this field identifies each VLAN that is being
configured.
Circuit ID
The administrative mode of the circuit ID. When enabled, if a client sends a DHCP
request to the device and the client is in a VLAN that corresponds to the S-VID,
the device adds the client's interface number to the Circuit ID sub-option of
Option 82 in the DHCP request packet. This enables the device to reduce the
broadcast domain to which the server replies are switched when the broadcast
bit is set for DHCP packets. When this bit is set, the server is required to echo
Option 82 in replies. Since the circuit-id field contains the client interface number,
the Layer 2 relay agent can forward the response to the requesting interface
only, rather to all ports in the VLAN).
Remote ID
The DHCP remote identifier string. When a string is entered here, if a client sends
a DHCP request to the device and the client is in a VLAN that corresponds to the
S-VID, the device adds the string to the Remote-ID sub-option of Option 82 in
the DHCP request packet. This sub-option can be used by the server for
parameter assignment. The content of this option is vendor-specific.
Click
Refresh
to refresh the page with the most current data from the switch.
DHCP L2 Relay Interface Statistics
The DHCP L2 Relay Interface Statistics page shows statistical information about the Layer 2
Relay
requests received on trusted and untrusted interfaces. An interface is untrusted when the DHCP Layer 2
relay trust mode is disabled.
To access this page, click
Switching
>
DCHP Snooping
>
L2 Relay
>
Statistics
in the navigation menu.
Configuring Switching Information
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